1. Field of the Invention
The present invention relates to an LED package using a Si substrate and a fabricating method of the LED package, and more particularly, to an LED package using a Si substrate in which a metallic heat dissipating unit is provided in a side opposite to a side on which an LED is mounted to effectively dissipate heat generated from the LED to the outside for preventing degradation of the LED and increasing the lifespan of the LED, and a fabricating method of the LED package.
2. Description of the Related Art
Light emitting diode (LED) is a diode that emits light using energy generated when injected electrons and holes are recombined. Examples of the LED are red LEDs using GaAsP or the like, and green LEDs using GaP or the like. In addition, nitride semiconductors using nitride (e.g., GaN) are widely used as photoelectric materials and essential materials of electronic devices because of their good physical and chemical properties. Nitride semiconductor LEDs are drawing attractions. The nitride semiconductor LEDs generate light in range of red, blue, and ultraviolet. With the breakthrough in brightness of the nitride semiconductor LEDs due to the technical development, the nitride semiconductor LEDs are applied to many fields, such as full-color electronic display boards and lighting devices. Various kinds of packages for mounting the LEDs are fabricated, depending on applications of the LED.
LED packages can be fabricated using various materials. Specifically, LED packages have been recently developed which use a silicon (Si) substrate having good processability and relatively good heat conductivity. An LED package using a Si substrate is disclosed in U.S. Pat. No. 6,531,328. The conventional LED package is illustrated in FIG. 1.
Referring to FIG. 1, in the conventional LED package 10, an LED receiving portion is defined by forming a groove in a predetermined region of a Si substrate with flat top and bottom surfaces, and insulating layers 12 are formed in the top and bottom surfaces of the processed Si substrate 11. Then, a conductive via hole (h) is formed to pass through the LED receiving portion and the bottom surface of the Si substrate. An upper electrode 14 is formed to be electrically connected to an LED 16 on the LED receiving portion, and a reflective layer 13 is formed on an inclined face of the groove and the top surface of the Si substrate 11. Depending on the mounting methods of the LED 16, the reflective layer 13 may be used as the upper electrode. In this case, the reflective layer 13 has to be formed of conductive metal with high reflectivity. In FIG. 1, the reflective layer 13 is used as the upper electrode connected to one electrode terminal (a negative terminal or a positive terminal) of the LED 16, and the other terminal of the LED 16 is connected to a separate upper electrode 14 through a wire. Then, a lower electrode 15 is formed to be electrically connected to the reflective layer 13 and the upper electrode 14 through the conductive via hole (h). The groove for the mounting of the LED is filled with a resin material or the like. Through the above processes, the LED package is completed.
Meanwhile, for applications (e.g., lighting devices) requiring high brightness, the LED consumes more power and thus a large amount of heat is generated from the LED. If the generated heat is not effectively dissipated, characteristics of the LED may be degraded or lifespan of the LED may be reduced.
In consideration of heat generated from the high-brightness, high-power LED, when the mounted LED is a high-power LED generating a large amount of heat, the heat dissipation is achieved by adjusting the thickness of the Si substrate, because the conventional LED package 10 of FIG. 1 does not have a separate heat dissipating unit. However, this method has a limitation in improving the heat dissipating efficiency. Therefore, even the use of Si substrates with good heat conductivity cannot solve the thermal degradation of the LED characteristics and the reduction in the lifespan of the LED.